Noise-induced hearing loss (NIHL) continues to be one of the most common occupational disorders, even in workplaces with OSHA-compliant hearing conservation programs (HCPs). Prevention of occupational hearing loss and development of better tools to assess HCP effectiveness are top priorities of the National Occupational Research Agenda (NORA) for manufacturing. This proposal will build on a unique relationship between the research team and a major manufacturing company to develop a comprehensive, "mixed method" approach for assessing HCP effectiveness. This research will also examine the effect of innovative technologies for hearing loss prevention that have been implemented in some study facilities. The study aims are to 1) recruit 10 locations and determine observed vs. expected rates of high frequency hearing loss for workers at each facility, 2) Perform quantitative analyses of the facility audiometric databases, including proposed ANSI methods for assessment of HCP effectiveness, 3) perform onsite qualitative analyses of HCP components using focus groups and interviews, and 4) combine and compare quantitative and qualitative assessments using mixed methods and multivariate approaches. This research will result in the development of a practical tool for assessing hearing conservation effectiveness and enhanced prevention of noise induced hearing loss. PUBLIC HEALTH RELEVANCE: This research addresses an urgent need to better assess and improve hearing conservation programs nationally. It has the potential to affect daily hearing conservation practice affecting millions of noise exposed workers in this country. The results of this study could have major research to practice (r2p) implications for hearing conservation, identifying important new opportunities for the prevention of noise-induced hearing loss, one of the most prevalent occupational diseases.